SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f4366df9c50588a5acdcc3ae9601022ab5188731076c175968f776cced5ff5d7' 
  AND token = 'PiPDDUxr7TNNlmpi+b1L7pMQpVwCL07TYEnAuurI+eM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}